yum wants to remove my kernels, why?

[Jeff Spaleta]

On 1/16/06, Timothy Murphy <tim at birdsnest.maths.tcd.ie> wrote:
> but in my view the default should be to keep the current, working kernel
> as the default (as I believe it used to be).

This makes for a very poor default for systems managed by novice fedora users.
Novice users may not realize that they need to reconfigure their grub
to take advantage of a security update kernel. Its very important that
the default configuration is one that makes booting into security
kernel updates as automatic as possible. For people with enough
experience using Fedora to competently manage multiple remote systems,
the configuration file /etc/sysconfig/kernel can be used to disable
this default.

> Also I don't see why any old kernels should be removed automatically.
> Surely it is easy enough to do that if one wants to?

Its actually not as easy as you think for novice users. The kernel is
rather special in a lot of ways, including the parallel package
installation mechanism which is used to install kernel packages. 
Novice fedora users may not understand that the package managers are
handling the kernels in a special way compared to other packages.
Novice fedora users may never realize that there are multiple kernels
installed and it is quite possible in the lifetime of a normal fedora
release to install so many kernels that /boot runs out of space if the
default partitioning is used. This sort of out of space condition
leads to confusion, confusion that can very well lead to big problems
when a novice user attempts to clean up the space. Watching novice
users come into #fedora looking for help cleaning up there system
because they attempted to remove kernels correctly isn't fun at all.  
It's a lot easier to explain to them how to boot into their older
kernel from the grub menu and help them troubleshoot the new kernel,
if the new kernel fails to boot correctly.

For people, including myself, who want to keep older kernels around
the configuration file  /etc/yum/pluginconf.d/installonlyn.conf
is provided in which the defaults can be overridden.

> I run yum automatically on a remote machine, and have had some problems
> with new kernels being installed and run automatically.

Please understand that your situation isn't the situation that is
designed for when defaults are established. You have the ability to
reconfigure both the installonlyn plugin in yum which removes old
kernels as well as th ability to reconfigure whether the new kernel is
the new boot default in grub  by reconfiguring  /etc/sysconfig/kernel.

-jef